AJP - Regu Journal of Neurophysiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Regul Integr Comp Physiol 239: R497-R504, 1980;
0363-6119/80 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Takahashi, J. S.
Right arrow Articles by Menaker, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Takahashi, J. S.
Right arrow Articles by Menaker, M.

AJP - Regulatory, Integrative and Comparative Physiology, Vol 239, Issue 5 497-R504, Copyright © 1980 by American Physiological Society

ARTICLES

Interaction of estradiol and progesterone: effects on circadian locomotor rhythm of female golden hamsters

J. S. Takahashi and M. Menaker

The phase and activity level of the locomotor rhythms of female golden hamsters (Mesocricetus auratus) vary in synchrony with the 4-day estrous cycle. We investigated the effects of estradiol and progesterone administration in ovariectomized hamsters to explore the interaction of these two ovarian hormones in modulating circadian locomotor rhythms. Silastic implants of estradiol shorten the period length of the rhythm, change the pattern and level of activity, and decrease the observed variance of the activity onset. Progesterone implants have no effects on the rhythm when given alone; however, when progesterone is given in combination with estradiol, all three estradiol-induced changes are blocked. These results correlate well with the observed locomotor behavior of normal female hamsters. If the levels of both estradiol and progesterone in the serum are taken into account, this correlation holds for a number of hormonal conditions including those found during the 4-day estrous cycle as well as during pregnancy and lactation. These data suggest that progesterone antagonizes the effects of estradiol in the normal animal and that the interaction of estradiol and progesterone modulates the circadian activity of female hamsters on a day-to-day basis.


This article has been cited by other articles:


Home page
 Am. J. Physiol. Endocrinol. Metab.Home page
T. J. Nakamura, M. T. Sellix, M. Menaker, and G. D. Block
Estrogen directly modulates circadian rhythms of PER2 expression in the uterus
Am J Physiol Endocrinol Metab, November 1, 2008; 295(5): E1025 - E1031.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online